A student is investigating the affect of different salts on melting points. Four patches of ice of equal size are roped off and
a different type of salt is poured on each one receives table salt (NaCl), one receives Calcium Chloride (CaCl2), one receives Potassium
Carbonate (KCO3) and the fourth receives Inert sand instead. Each patch receives an equal amount of salt or sand. The student
measures the volume of ice remaining and subtracts it from the original volume of ice to see how much melted away. What is the
dependent variable?
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A. The type of salt applied to the ice.
B. The amount of lee that melted.
C. The ice that received sand.
D. The size of the Ice patches
The dependent variable is more of what results from an action during an experiment. It is actually what is being tested for. In the experiment, the scientist seeks to understand the effect of salts on melting point of ice. He selects the different salts which can cause a ice to melt (independent variables) then he sets up to find out the effect of the salt on the ice.
He cannot control how much ice will melt. The properties of the salts would determine the extent and rate of the dissolution of the ice pack. This is the dependent variable which relies on the nature of the salt.
Telescopes on Earth and in orbit around Earth provide scientists with information about our solar system. That information is used to plan where spacecraft fly and where they “point their cameras.” NASA and other agencies send robotic spacecraft to fly by, orbit, or land on other planets and moons.
